Sansui RA 990 Service Manual

Page 2

1. BLOCK DIAGRAM

L-ch
our PUT Co)
Ivrm
05 I
IN PUT Co) 9
TAPE-I (MIXING
(PLAY) : BALANCE IVRs
I
TAPErz | '2
(PLAY) ' /
I /
I l/DEPTH
TAPE-I I __1 /
IREC) I [x
o S 2 I /
TAPE-2 ' /
(REC) : AUDIO DRIVER AMP REVERSE AMP
I I
_ICIGUITARI AMP I IVR2 I
gVRIa IVth I IVRIc I
I ' I I
|
Eg+$ I % IlCda . IlC4n IICG
' I
CH-I '/ - I
LEVEL LEVEL IVEIXIME E J, I
I PANPOT _ I
I I R C l j|C7
R-ch R-ch 0+2 I
: IvRa
I
l
I
| /
I //DEPTH
| / I ICB
I
I /
I
y/ R-ch
V
R-ch
L J

OSince the Reverberation Circuit, BBD IC and BBD clock Drive lC employed RA-990 are
similar to those of RG-7, the explanation of these circuits are omitted from this manual,
therefore please refer to the page 2 on service manual of RG-7.

OSince some of capacitors and resistors are omitted
from parts lists in this Service Manual, refer to the
Common Parts List for capacitors & resistors,
which was appended previously to Sansui Manual.

2. PARTS LOCATION & PARTS LIST

2-1. F-3714 Control & Mic Amp. Circuit Board (Stock No.00689101)

Component Side 7 _

Parts List
Parts No. Stock No. Description Parts No. Stock No. Description
olC 0J1 46266300 Jack, MIC (GUITAR)
le1 03607700 NJM45580 OIC
1 072089 0 NJM4558D-X
IVRI 46265800 250kn VR, MIXING BALANCE gIC 0
jVR2 46266200 250kn VR, MIC PANPOT gVR1 46266100 20k!) (8), VR, MIC LEVEL